Information recording medium and method and apparatus for recording and reproducing information using the same
CA 2206502 C · Owner: Suzuki, Yoshio · Inventors: Sugiyama, Hisataka; Fushimi, Tetsuya; Miyamoto, Harukazu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A disk-like information recording medium includes recording areas provided in both of a groove portion and a land portion. The information recording medium is divided into groups of a plurality of areas each track is divided into circular arc-shaped sectors having the same central angle arranged to be radial in the radius direction identification information is provided at every sector each track is divided into groups in such a manner that lengths of the circular arc-shaped sectors become almost constant among the groups and the groove portion and the land portion are wobbled in the radius direction of the information recording medium. When the groove portion information track and the land …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed July 25, 1997 and granted February 9, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 25, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 25, 2019.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.